The role of the subiculum as a network player in physiological and pathological conditions
Final Report Abstract
Epilepsy is a common neurological disorder and about one-third of patients are drugresistant, meaning that the seizures cannot be controlled with medication. In addition, the seizures are almost unpredictable for those affected. This often means a high disease burden for the patients. Epilepsy is now understood as a disease of neuronal networks. In addition to epileptic seizures, epileptiform discharges in the form of interictal spikes also occur in these networks. The latter show circadian and multidien rhythms both in humans with epilepsy and in rodent models, which allow conclusions to be drawn about current seizure risk. During my grant period, I performed electrophysiological measurements (local field and single cell activity) in the hippocamus and subiculum in a model of temporal lobe epilepsy in rats. We developed a particularly stable implant to be able to take measurements lasting weeks. During the measurements, this implant survived several hundred epileptic seizures without damage. Furthermore, a simple and safe explantation of the expensive probes was possible and they could be reused several times. I detected the interictal spikes with a clinically established algorhythm. These were found to occur significantly more frequently during the day than at night in both the hippocampus/subiculum and the cortex. Moreover, in a subset of the measurements, the spikes also showed a significant multidien rhythmicity, with which the frequency of epileptic seizures in the animals also strongly correlated. Here, the number of seizures increased before the rate of spikes increased. Currently, I am evaluating behavioral activity (sleep stages, wakefulness) based on the recorded videos. In addition, I am currently processing the high-resolution electrophysiological data to extract single-cell activity from this. The analyses should be completed by mid-2024. In a side project, I optimized a self-designed algorithm for the detection of epileptic seizures, so that it could be used in a data set with long-term recordings in mice. This improved the sensitivity and at the same time significantly shortened the processing time.
Publications
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The role of the subiculum as a network player in a model of temporal lobe epilepsy. GDR NeuralNet conference, Lyon, September 2022
Matthias Dipper-Wawra, Antione Ghestem, Dominika Guttenova & Christophe Bernard
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Long-term near-continuous recording with Neuropixels probes in healthy and epileptic rats. Journal of Neural Engineering, 20(4), 046003.
Ghestem, Antoine; Pompili, Marco N.; Dipper-Wawra, Matthias; Quilichini, Pascale P.; Bernard, Christophe & Ferraris, Maëva
